CPU/Motherboard Issues? (SOLVED)

[Grod_The_Giant]

My desktop is encountering some sort of error when I turn it on, where the lights and fans work normally but absolutely no signal is sent to the monitors, and I'm about at the end of my rope trying to troubleshoot it. Any suggestions?

Spoiler: The Rig

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Motherboard: MSI Z270 Gaming
CPU: Intel i7-7700k 4.2GHz
Graphics: GeForce GTX 980
RAM: 16GB CORSAIR Dominator Platinum
Power Supply: LSP Ultra 750W ATX Power Supply. Plugged into a surge protector/battery backup thing, if it matters.
Fan: Rocketfish something or other. Nothing fancy, just a basic heatsink + fan.
Case: Some giant black dinosaur thing that looks like it's been through the wars.

Spoiler: The Event

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My computer had been getting a little slow lately, in that hard-to-define "I can't point to anything in particular but I've been using this machine for years and something feels off" sort of way. I was also having the occasional (once every hour or three) graphics error where both monitors would go completely blank for a moment before returning to normal with no apparent interruption.

Nevertheless, it was still working pretty well, and I decided to finally try the copy of Guardians of the Galaxy that had been sitting in my Steam library for months. It was initially very reluctant, stuttering even with everything turned down to the absolute minimum--I later noticed that my graphics card was actually slightly below the game's specifications--but after downgrading my graphics driver it suddenly started working gorgeously even on medium settings.

I did notice that the machine was running hot, with a hot dust sort of smell, so I made sure not to leave GotG running for too long at once. I apparently put in about four hours over two or three sessions, but at the time of The Event I was just watching Netflix and working on a Word document. And then--

Bloop!

The computer instantly turned off. No warning, no freezing, nothing.

Spoiler: Troubleshooting To Date

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Initially I figured that my computer had probably overheated. GotG was probably the newest triple-A game I've played, it did feel hot, and the tower sits on the floor under my desk (exhaust vents clear) and I have a dog, cat, and depression.

I let it sit for an hour or two, then tried turning it back on. The fans and hard drive started to spin, lights came on everywhere, and nothing happened. I didn't even get a logo or BIOS screen. Both my two monitors and the TV-- all connected using different types of cable, because I'm apparently that sort of goblin--was blank, with the little "no signal detected" error bouncing around. Went to bed and tried again in the morning; same result. (Both times I walked away and let it run for a bit in case it was just being slow to boot; didn't help either.)

So maybe I bumped the case and knocked something loose? I hefted the tower up on my desk and checked connections--nothing was noticeably wrong, apart from a bunch of dust. Still, maybe that was the problem, so I went at it with a duster, some q-tips, and a can of compressed air. Dust dust dust, sneeze sneeze sneeze, that should do the trick. Reconnected the mouse, keyboard, and monitor, turned it on...

Nothing.

Cue some concerned googling. The only thing I could think of was that I burnt out my CPU; while I couldn't make out a beep code, the motherboard had a steady red warning light for a CPU error. I tried disconnecting the graphics card and/or RAM with, changed the CMOS battery, tried different display ports--nothing. I couldn't tell if there was any physical damage to the CPU; there were no obvious scorch marks but I didn't really know what was dried thermal paste and what wasn't.

I go online to find a new CPU; after a bunch of double-checking, I find one that looks like it should be compatible. (In fact, I later realized, it was the exact same model as the one I'd been using before.) I also grab a new fan, since that seemed worth replacing after a heating issue, and a SSD because...well... because I'd been wanting one for a while and I was already ordering parts and a new processor might mean resetting my OS anyway, so why not?

Wait wait wait. Stuff arrives.

I pull out the old CPU and fan and slot in the new models (regularly touching the metal case to ground myself). Re-seat the graphics card. Realize it's covering the spot where I need to put the SSD, sigh, and re-seat it yet again. Finally I put everything back together, hook the monitor/keyboard/mouse back up, and hit the power switch.

Nothing.

I repeat my previous tests with removing graphics card, RAM, hard drive, CMOS battery, and switched where the monitor was plugged in a few times. I take the fan off, wipe up a little excess thermal paste, and re-seat the CPU. None of it helps--I'm still getting the exact same error light. And a headache.

So, uh... yeah. What do I try next?

Update: Further attempts that changed nothing:

• Shorting the BIOS jumper.
• Unplugging and re-plugging the power connections to the motherboard.
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tl;dr: Computer was hot, shut down, and now won't even reach BIOS. Cleaning, re-seating, and removing parts didn't help; nor did replacing the CPU. Help?

Spoiler: Final Diagnosis

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Conclusion: After lugging my giant metal box of a machine to a professional, it was determined that part of the power supply had failed--it wasn't picking up the signals from the cpu that it needed more power, so it never managed to turn on. With that replaced, the computer works fine again.

(Well, one of the RAM slots on my motherboard also broke who knows how long ago, but that's another thing entirely)

Tl;dr: I should have bought a ten dollar multimeter before waiting a week for a hundred dollar professional consult.

[sihnfahl]

Remove all RAM. Try to boot.

Then, use the jumper to reset CMOS.

Plug in ONE RAM stick into the primary slot, then try booting.

[factotum]

Silly question: given the primary symptom is that you're getting no signal to the monitor, how do you know it isn't the graphics card that's gone to the great scrapyard in the sky? Does the CPU you currently have in there have on-board graphics that you can test via the motherboard output?

[Gnoman]

Many MSI motherboards have a 4-led array labeled "EZ-Debug". Pop the side off your case and see if yours does.

[Grod_The_Giant]

Remove all RAM. Try to boot.

Then, use the jumper to reset CMOS.

Plug in ONE RAM stick into the primary slot, then try booting.

I've tried the RAM steps. I couldn't figure out what the jumper in question is, but I did replace the CMOS battery-- removing the old one should have had a similar effect, right?

Silly question: given the primary symptom is that you're getting no signal to the monitor, how do you know it isn't the graphics card that's gone to the great scrapyard in the sky? Does the CPU you currently have in there have on-board graphics that you can test via the motherboard output?

I've tried the port on the motherboard itself, with and without the graphics card installed. Nada. Even if my CPU doesn't have on-board graphics for some reason, I should at least have seen a bios screen, right?

Many MSI motherboards have a 4-led array labeled "EZ-Debug". Pop the side off your case and see if yours does.

It does; the first light (the one labeled "CPU") turns a steady red when powered on.

[sihnfahl]

Silly question: given the primary symptom is that you're getting no signal to the monitor, how do you know it isn't the graphics card that's gone to the great scrapyard in the sky? Does the CPU you currently have in there have on-board graphics that you can test via the motherboard output?

Many MSI motherboards have a 4-led array labeled "EZ-Debug". Pop the side off your case and see if yours does.

Fifth paragraph, third spoiler. Red CPU light, tried video card.

I doubt it's the CPU, since he got a new one.

What specific model of motherboard, as well?

Power supply looks sufficient, but how about the additional 4 pin ATX power?

[Gnoman]

Sorry, I read that as "HDD Light", and thought he was talking about the case LED.


Try unplugging all the power connectors to the motherboard and plugging them back in. Sometimes the connections get loose and you can't tell.

[sihnfahl]

Even if my CPU doesn't have on-board graphics for some reason, I should at least have seen a bios screen, right?

You have a k, not a kf model, so your onboard graphics aren't disabled.

And yeah, you should have seen a bios screen if it's posting, if your monitor is hit up to the DVI port on the motherboard itself, and the video card out.

Try the BIOS reset jumper.

[Grod_The_Giant]

Try the BIOS reset jumper.

I found the reset jumper-- labeled JBAT1 in both my manual and on the motherboard itself-- to be a pair of pins rather than a switch. I don't have anything like a proper jumper cap, but I tried connecting the two pins with the tip of a screwdriver and with a penny. Would that rule out a bios problem, or should I go buy some jumper caps just in case?

Try unplugging all the power connectors to the motherboard and plugging them back in. Sometimes the connections get loose and you can't tell.

... ****, maybe it is a power supply issue? I re-seated the main plug and it did nothing. Then I saw that there are two "cpu_pwr" ports on the diagram in the manual. One was plugged in; the other doesn't seem to exist (and has a plastic covering piece over where it should be). I tried re-seating that one and now it's not turning on at all.

Edit: nope, I'm a moron who also unplugged the power button on the front. With it reconnected the system once again turns on but does not reach bios.

[sihnfahl]

I found the reset jumper-- labeled JBAT1 in both my manual and on the motherboard itself-- to be a pair of pins rather than a switch. I don't have anything like a proper jumper cap, but I tried connecting the two pins with the tip of a screwdriver and with a penny. Would that rule out a bios problem, or should I go buy some jumper caps just in case?

All that does is reset all motherboard to the default, so it SHOULD be trying the onboard video as the first option for display.

It doesn't matter HOW you short it, just that you short it for about 10 seconds.

Also, what model of the RAM are you using?

[Grod_The_Giant]

All that does is reset all motherboard to the default, so it SHOULD be trying the onboard video as the first option for display.

It doesn't matter HOW you short it, just that you short it for about 10 seconds.

Also, what model of the RAM are you using?

CORSAIR Dominator Platinum-- this, specifically, based on my order history. Also this exact motherboard and this CPU.

[sihnfahl]

Okay, how do the connectors at the power supply look?

Any smells when you turn it on / sounds?

[Grod_The_Giant]

Okay, how do the connectors at the power supply look?

Any smells when you turn it on / sounds?

I mean... They look like cables and plugs. Nothing obviously freyed or scorched.

There are a few fast, feathery chirps when I first power up; they go by so fast I haven't been able to count them. No smells that I can detect, tho my nose works very poorly.

[Keltest]

I mean... They look like cables and plugs. Nothing obviously freyed or scorched.

There are a few fast, feathery chirps when I first power up; they go by so fast I haven't been able to count them. No smells that I can detect, tho my nose works very poorly.

I would double check that all the power cables are plugged in fully and correctly at both ends. Most should have a clip on them to make sure they don't come loose, at least on the power supply end. That can be a good indicator whether it's in fully or not, since it won't latch correctly if it isnt.

[Erloas]

If you're not getting any output and no beep codes, then it is either CPU, motherboard, or power supply. The power supply are the most likely to have issues with long term overheating and diminished output, though 750W should be fine in terms of power, even with diminishing output (which doesn't mean it can't fail). While the fans still spin up, there are 3 different voltage levels, and likely 2 separate 12v circuits. The fans only need 12v to power up, but the rest of the system won't work if the others aren't there.

Short of having a replacement, there is no great way to test those parts apart. At least your system is new enough that you can get replacement parts and they would have some value.
I don't know anything about your power supply manufacturer (though I haven't been in the loop for some years), and that is always suspect, it is also the easiest and most universal part that you can get.
After that I would say the motherboard is the most likely to fail, then the CPU. Although if you're getting to the point in replacing the motherboard it might just be time to replace both motherboard and CPU for a newer platform.

[Keltest]

If you're not getting any output and no beep codes, then it is either CPU, motherboard, or power supply. The power supply are the most likely to have issues with long term overheating and diminished output, though 750W should be fine in terms of power, even with diminishing output (which doesn't mean it can't fail). While the fans still spin up, there are 3 different voltage levels, and likely 2 separate 12v circuits. The fans only need 12v to power up, but the rest of the system won't work if the others aren't there.

Short of having a replacement, there is no great way to test those parts apart. At least your system is new enough that you can get replacement parts and they would have some value.
I don't know anything about your power supply manufacturer (though I haven't been in the loop for some years), and that is always suspect, it is also the easiest and most universal part that you can get.
After that I would say the motherboard is the most likely to fail, then the CPU. Although if you're getting to the point in replacing the motherboard it might just be time to replace both motherboard and CPU for a newer platform.

If i'm reading the earlier posts right, the CPU was replaced between now and the initial crash, which makes a CPU issue unlikely unless it was wildly mishandled being installed.

[Grod_The_Giant]

Conclusion: After lugging my giant metal box of a machine to a professional, it was determined that part of the power supply had failed--it wasn't picking up the signals from the cpu that it needed more power, so it never managed to turn on. With that replaced, the computer works fine again.

(Well, one of the RAM slots on my motherboard also broke who knows how long ago, but that's another thing entirely)

Tl;dr: I should have bought a ten dollar multimeter before waiting a week for a hundred dollar professional consult.